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C. E. LUCKE.

APPARATUS FOR BURNING EXPLOSIVE GASEOUS MIXTURES.

APPLICATION FILED sEPT.8,19|5. RENEWED 0cT.3l.1918.- 1,313,196.

Patented Aug. 12, 1919 3 SHEETS-SHEET l.

MII

Attest nventor:

v Atty C. E. LUCKE.

APPARATUS FOR BURNING EXPLOSIVE GASEOUS MIXTURES.

APPLICATION FILED SEPLS, 1915. IIENEwED OCT. 31. I9I8.

1,313,1 96. Patentedmig. 12,191

E 3 sIIEETs-sIII-:ET 2.` EE 5&0

0000 o 00900 o o oOo 0 O 0 o O oo o 0o OOO O O O O oo o 000 00000-00000O 0 0 0 O O 0 ooo@ ooo oo o 000000000 o 0000 o Attest: A I l Inven or:@Vw 3m A I M752, WSW-w f A.; Atty C. E. LUCKE. l APPARATUS FOR BURNINGEXPLOSIVE GASEOUS MIXTURES. APPLICATION FILED SEPT.3|19|5 RENEWED OCT.31| 191B.

Attest: g! Ingentor: Ela-M) @5er/f M!" 'f/f UNITED sTATEs PATENT oEEicECHARLES E. LUCKE, 0F YORK, N.'Y.

APPARATUS-ron BURNING ExPLosIvE GAEOUSMIXTURES. I

Specification of Letters Patent.

Application led. September 8, 1915, Serial No. 49,561. Renewed October31, 154318. Serial No. 260,5444

To aZZw'wm it may concern:

Be it known that I, CHARLES E. LUCKE,

a citizen of the United States, residing at New York city, in the countyof New York and State of New York, have invented certain newand usefulImprovements in Apparatus for Burning Explosive Gaseous Mixtures, fullydescribed and represented in the following specification and theaccompanying drawings, forming a part of the same.

This invention relates to apparatus for burning explosive gaseousmixtures. The obj ect of the invention is to provide apparatus suitablefor use generally and by which localized and non-explosive or continuouscombustion of such mixtures may be maintained With the mixture suppliedunder'comparatively low pressure.

Continuous and localized combustion of vexplosive gaseous mixtures maybe maintained by feeding the mixture through a passage With a velocitygreater than the rate of propagation of inflammation of the mixture inorder to prevent back-iashing and then rapidly reducing the flowvelocity and burning the mixture Where the' flow velocity equalsthe rateof propagation of inflammation of the mixture, and also by feeding themixture with a velocity less than the rateoi:l

propagation of inflammation of the mixture through a flame interruptingpassage or orilice which is of such width that back-Hashing will beprevented by the cooling action on the mixture of the walls of thepassage or orifice, the mixture then burning as it escapes fromthepassage or orifice. In an apparatus for burning explosive gaseousmixtures in either of these ways, where the combustion takes placeclosely adjacent to the discharge opening, it is necessary that theapparatus be constructed so as to prevent heat from being conductedbackward through the Walls of the supply passage to such extent astoheat the walls of the mixture supply chamber to the temperature ofignition of the mixture, and in an apparatus operating on the principleof the Harrie-interrupting passage, to prevent back-lashing it isnecessary that the Walls of the llameinterrupting passage or passagesshall be kept at such comparatively ,low temperature that theyv maycontinue to perfom their function of cooling, or abstraeting heat from,the mixture itself flowing through ,the

passage or passages suiiciently to prevent` ignition thereof by heatcommunicated back` throughthe mixture and consequent backi'la'shing.,The difficulty of preventing backward 'conduction of heat through thewalls of the supply passages is especially troublesome in apparatus inwhich the mixture is supplied to the place of combustion through a largenumber of closely adjacent passages.

U. S. Patents Nos. 1,113,171, granted on an application of FrankCreelman, and 1,113,174, granted on an application of Charles E. Luckeand Frank Creelman, both Patented Aug. 12,1919.

dated October 6, 1914,`sh0w apparatus constructed to prevent backwardconduction of heat from the 'combustion zoneto the supply chamber tosuch an extent as might cause ignition of the mixture in the supplychamber; and in my application Serial No.

7 68,7 7 4, filed May 20, 1913, there is disclosed.

a low pressure birrner or apparatus for lconstruction, of the apparatusof 'each of said patents and of said application is such that the heatis conducted away from the walls of the mixture passages to suchanextent as to secure the desired results, and in each of them thepassages through which the mixture is supplied to the place ofcombustion lead from amixture supply chamtilt)v ber located close to thepl-ace of combustion so as to reduce the length of the small supplypassages *and thereby avoid excessive resist- .ance to ilow of themixture. f

A principal object of the present invention is to-still further reducethe resistance to flow of themixture in passing rom the mixture chamberto the place of co bustion so as to further yreduce the pressurerequired to be maintained in the mixture chamber. To lreduce the Howresistance as much as possible, it is necessary to reduce as much as'possible the length of the small passage or passages through which themixture Hows to the combustion space. I therefore provide in apparatusembodying thel present invention very short discharge pastivity, Wouldnot have the necessary conducting capacity for carrying heat away fromthe Walls of the orifices rapidly enough to maintain such Walls at thedesired comparatively low temperature, I form the metal body in Whichthe discharge orifices are located so that it shall have the neces sarylarge heat conducting capacity by making it of such form that it shallhave a rapidly increasing cross-section in the direction of the flow ofheat from the Walls'of each orifice and shall be ofy suchcross-section'or mass at any part that such part shall have the requiredheat conducting capacity for carrying away at the necessary rate allheat reaching such par-t from the Walls of any one or more of thedischarge orifices. This result is most desirably attained by providinga body of-metal of high heat conductivity of the required mass orlcross-section and forming lthrough it discharge passages leading from asupply chamber to the place of combustion constricted at their dischargeends to form the desired discharge orifices. s

Suitable means must also: of course be provided for dispersing the heatconducted out- Ward through, the metal body, and vfor this purposesuitable dissipating surfaces of large extent are most desirablyprovided for discharging the-v heat directly to the surroundingatmosphere. It is desirable that the burner or apparatus shallnot bedependent upon the provision of any circulatin fluid for carrying awayheat from the meta body, but the invention in its broade-raspeet 1s notto,be limited in thisrespect. The

ybody in vWhich the discharge orifices are formed should, as beforestated, be of a material off high thermal conductivity, and

most `desirably is formed of a metal of a conductivity of the class ofthat of copper, aluminum, etc., and including suitable a1- loys;and ofthese metals I `consider aluminum the best, for the reason that while itis not the best conductor, it is the best for -cost and availability.

4 Theunvention has been made especially with the idea of providing aburner for explosive gasous mixtures intendedfor burning mixturesupplied under a ressure'not sufiieient to cause the mixture to thedischarge orifice or orifices with a velocity in excess of the rate ofpropagation of inflammation of the mixture, and in which back-flashingis prevented b the cooling action of the Walls of the disc arge'orificeor orifices on the mixture flowing therethrough, such discharge orificeshaving a cross-section or Width sufficiently small to so act; and ofsecuring in such 'a burner the ovv through of the discharge orificeswith a minimum mixture flow resistance so that a suitable quantity ofmixture may be discharged through the orifice or orifices with a verylow supply pressure. The invention is also applicable to, and of greatvalue for, burners intended for burning explosive gaseous mixturessupplied under pressure sufficient to cause the mixture to flow throughthe dis- -charge orifice or orifices With a velocity greater than therate of propagation of iniammation of the mixture, and in which suchexcess flow velocity is depended on to prevent back-hashing, andlocalization of combustion is secured by rapidly reducing the flowvelocity of the escaping mixture. In such burners also, the reduction ofresistance to`floW of the mixture and consequent reduction of thepressure necessary to give the required velocity of discharge issometimes of great advantage. Such burners need not, of course havetheir discharge orifices of such small Width as to serveasfiame-inte'rruptin passages or orifices which prevent back-Has mg bycooling the mixture stream. But by providing burners havingflame-interrupting orifices with means for causing the mixture flowingfrom the orifices to spread out'rapidly With reduction of fiow velocity,they are made adaptable for burning explosive mixtures supplied under a`range of pressures including. pressures sufficient to cau-se the mixtureto flow through the discharge orifices with a veloc ity in excess of therate of propagation of inflammation of the mixture and pressures notsuflicient tocause such excess flow velocit through the dischargeorifices.

W en it is desirable to develop radiant heat With a burner not providedWith velocity reducingy means, some suitable solid matter is disposedwith reference tothe discharge orifices, so that it Will be heated toincandescence when the burner is in operation. Such matter should mostdesirably bev arranged so as not to reflect heat back to the metal bodyof the burner to any considerable extent. A hearth of fire brick orother suitable refractory material of lovv heat conductivity, formed-With fiaring holes registeringl with thel discharge orifices andcovering practically all of the outer or hearth Wall of the'metal bodyWithout offering any gas flow resistance, is desirably provided. Theside Walls of the flaring holes of such hearth Will become radiantthemselves, but may be supplemented by suitably ioo iammation. Forproducing the highest temperature, the oxygen should be undiluted andthe mixture should contain oxygen and combustible matter in chemicalCombiningproportions at the time of combustion; but

- theremay be an excess of either the combustible matter or thecombustion supporting gas within the limits which determine the propertyof self-propagation. Themixture may be varied in this respect accordingto the desired character of the products ofl combustion, that is,whether it is desired that the products shall be neutral, oxidizing orreducing. Also, the mixture may of course contain neutral gas such isnitrogen, carbon dioxid orfwater vapor, so long as the amount' of suchneutral gas is not suicient to make the mixture non-explosive.`

The accompanying drawings illustrate lvarious forms of apparatus made inaccordance with the present invention. In said f drawings:

in Fig. 1 with the layer of refractory mate- Figure v1 is -a sectionalview taken on line 1 1 of Fig. 2 of a burner made in accordance with theinvention; f

Fig. 2 is a plan view of the burner shown rial or hearth removed;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a view'similar to Fig. 3 but showing the burner supplied witha combustion localizingbed'; i

Fig. 5 is a sectional view of a single slot burner shown asprovided-witha combustion localizing bed;`

Fig. 6 is a plan view ofthe burer shown in Fig. 5 wlth the combustion,localizing bed removed;

Fig. 7 is a section taken on line 7-7 of Fig.5; 'vv Fig. v8 is asectional view of another form o f burner embodying features of theinventol.; 9 I

1s a in 8;

Fig. .10 is a sectionalview of a burner plan view of the burner shownwhich is a modication of the form of burner shown in Figs. 8 and 9;

Fig. .11 is a' sectional view of another illustrative form of burner,and j Fig. 12 is a plan view of the burner shown by Fig. 11i` Figs. 1, 2and 3, the burner shown in these figures vcomprises a metal body 10formed to provide a plurality of discharge orifices 1.1 through whichexplosive gaseous mixture from a mixture chamber v12 1s discharged to beburned. 'The discharge orifices in the parallel slots extending throughthe upper wall of the metal body'lO. The discharge orifices 'are madevery short in the direc- .tion of iiow of the mixture through them,

and below the orifices and between the oriiices and the mixture chamberproper the i metal of the body is Aextended vdownward or inward betweenthe discharge slots or oriiices so as to provide acomparatively'substantial body 13 of metal between the slots and-connected With the portions of the body beyond the ends of the slots.The lopenings or passages between such inwardly extending portions 13 ofmetal:` between the slots are of greater cross-sectional dimension thanthe slots, the walls of such openings most desirably, spreading outwardor away from each other in the directionsl both widthwise and lengthwiseofthe slots, so as to avoid resistance to How of the mixture and there-`by reduce the resistance to flow of mixture escaping'from the supplychamber to that minimum resistance offered bythe discharge orificeitself. The body may be considered as being formed withdischargepassages leading from the mixture chamber which are constrictedat their upper ordischarge ends to provide short portions Yor dischargeorifices of the desired cross-sectional dimension or'width. i

The walls of the passages or flow spaces leading to the dischargeorifices being as shown and as .above described, the metal body willhave the desired rapidly increasjlng cross-section in thedirection inwhich the body the heat conducted through it. It

is most desirable, however, and especially for small burners, not toresort to means involving forced" circulation in contact with the bodyof water or other cooling liquid or gas, but to secure the discharge ofheat from the body to the surrounding atmosphere by pror viding the bodywith an extended heat-dissipating surface of suitable area, and for Athis purpose' the body, itself suitably ex- Referring to the drawings,and first to* tended, may be provided with relatively thin ribsor ns' 14extending therefrom. The body is best extended downward about themixture chamber, and I consider it most delOl.

sirable to have the body extend completely.

about the mixture chamber, that is, that the mixture chamber shall beformed within the metal body as shown, as I thereby secure a largeextent of discharging surface of the body with simple construction. Theportions of the body extending downward and about the sides and bottomof t'he chamber are desirably made of adually decreasing thickness-since the requlred heat conducting capacity decreases in the portionsmore re`.

mote from the -discharge orifices by reason of the heat already disposedof.

When the cooling action of the walls of the discharge orifices on themixture passing through them is to be depended upon to pre- -ventback-flashing through the orifices and ignition of the mixture in thesupply chamber, the width of the orifices must of course be suiiicientlysmall to secure this result. While the maximum width of the orificeswill vary according to the character of the mixture to be burned,orifices of between .02'

and .03 of an inch in width will usually be found most suitable.

An inlet opening 15 isprovided to the mixture chamber through' which theexploinjector and through the discharge or pres-- .sure cone 18 to thesupply chamber.

The injector should be designed and the nozzle and combining tube set inproper .relative position, as by adjusting either one, to supply amixture containing the gas andv air in suitable combining proportions,and the gas should reach the injector under sufiicient pressure to causethe mixture in the supply chamber to be maintained under such pressureas will cause the mixture tosflow through` the discharge orifices inquantities sufficient for the desired rate of combustion, thoughnotpwith a velocity in excess of the rate of propagation of llamethrough the: mixture when no means for causing lateral spreading of themixture leaving the orifice is lprovided. The supply chamber should belarge enough to permit the mixture to move therein with suchcomparatively low velocity as to secure a substantially uniform supplyof mixture to all the discharge orifices.

A layer or hearth 2O ofvre brick or other suitable refractory materialof low heat conductivity is best provided covering the outer or hearthwall of the metal body and formed with outwardly flaring openings orholes registering with the discharge orifices. Such hearth or coveringlayer protects the metal body from a great deal of heat which wouldotherwise enter itand also provides walls adjacent the place Wherecombustion takes place which become highly heated and serve i as sourcesof radiant heat. thearing enings will refiect little if any heat back tothe metal body. As sources of radiant heat, they may also besupplemented by -a suit'abl disposed screen 21 of a sultable non-oxidizale metal, such as nickel or a nickel alloy, or other suitable materialbest formed with openings for the esca-pe of the products of combustion,such for example, as a perforated silica or metal plate or woven wirenetting. i

The metal body, in order that it shall have the necessary heatconducting capacity, is best-made, as before pointed out, of metal ofSuch Walls of high thermal conductivity such as copper or aluminum. Thebody may be formed of a single integral piece of metal or of separate.parts formed and secured together in anyV suitable manner so as not tointerfere with the flow of heat through the body from the walls of thedischarge orifices; In the burner shown; in Figs. 1, 2 'and 3,'the bodyis formed of -a series of bodysections a alter-V nating with thinspacing sections b, the end body sections being formed to provide endWalls for the mixture supply chamber. The intermediate body'sections areeach formed so that the metal extendscomplctely about a central openlngand is cut away at the top of the opening as shown to provide 'theportions 13 which extend downwardly .between adjacentJ dischargepassages. The spacing sections are of the same general form as the bodysections except that each spacing section has an opening through thetopfportion thereof of a length equalto and which de termines the lengthof the discharge orifice. l 4 The body sections and spacing sectionsarev shown as secured together by bolts wliich extend through lugsprojecting outward from the sections. Y r

In use, assuming the discharge orificesl of the burner to be of suchsmall width as to serve as dame-interrupting orifices, and as` sumingthe burner to be used as shown withtained undersuch low. pressuretherein that escaping mix- 4the velocity of. flow of the mixture throughi the discharge orifices will be lessl than or equal to or not much inexcess of the rate of propagation of inflammation of themixture, and themixture will burn at the discharge side of the orificesv or slightlywithin the orifices. Heat entering the body adjacent the orifices willpassthrough the body and `be discharged from the ns 14, and thetemperature of the walls of the orifices and other walls in contact withthe mixture will interrupting property of the discharge orifices will bemaintained. In a-properl designed burner having a body of aluminum orother metal of a. like order'of heat conductivity, the hottest parts ofthe body near the mixture exits will not be materially hotter than the-most distant parts, that is, by providing for sufficient amount of heatconducting capaci-ty of the body the temperature difference between theChottest and cooli lest parts of the body may be controlled in a pandserve as a source of radiant heat. The

screen 21, if provided, will also becomes,

highly heated and radiate heat.

If the burner is to be operated with such pressure maintained in themixture chamber as to cause the mixture to flow through the dischargeorifices with a velocity appreciably in excess of the rate ofpropagation of inflammation of the mixture, then means should beprovided for causing the mixture flowing from the discharge orifices tospread out with rapid reduction of its flow velocity. Fig. 4t shows aburner of the construction shown in Figs. 1 to 3 provided with a porousand permeable combustion bed of refractory material formed to cause themixture entering it from the discharge orifices with an excess lvelocityto spread out and advance with rapidly increasing cross-section anddecreasing velocity, such bed being shown as formed by broken, molded orother suitable pieces of highly refractory material such as alundum,chrome ore or magnesite, or fireclay, filled into the space between theflaring walls of 'the openings in the hearth or layer 20. The pieces orgranules forming the bed may be either loose or bonded together and mayvary in size according to the size, design and intended use`of theburner, and especially according to the thickness of the bed. A burnersuch as shown in Fig. 4 having discharge orifices of a widthsufficiently small to prevent back-flashing by cooling, or abstractingheat from, the mixture streams passing through the orifices may beoperated A with mixture maintained in the supply chamber under a rangeof pressures including those which will cause the mixture to bedischarged through the orifices with a velocity greater than the rate-of propagation of inflammation of the mixture and lower pressures whichwill not cause such excess velocity of discharge. through the dischargeorifices with a velocity less than the rate of propagation of in- Whenthe mixture flows flammation of the mixture,4combustion will take placeat or just within' the mouths of the orifices, but when the mixture isdischarged with a flow velocity appreciably in excess of the rate ofpropagation of'inflain- 70 mation, the mixture leaving the dischargeorifice. with such excess velocity will have its ve ocity reduced as itadvances through the combustion bed and the surface or zone ofcombustion will then locate within or at the outer surface of thebedwhere the reduced flow velocity equals the rate of propagation ofinflammation. When sufficient mixture is being burned, the combustionbed will become uniformly heated to a high state of incandescence Iandserve as a source of radiant heat. A If because of the small amount ofmixture being burned and the size of the granules the bed does notbecome uniformly heated, the radiating screen 21 85 may still beuniformly. heated to incandescence by the products of combustionescaping through the bed and passing the screen. Heat received byportions of'the body adj acent the place of combustion will be conductedaway and dissipated as before point- E ed out, so that ignition ofmixture 1n the supply chamber and in the flow passages 13 will beprevented, and the property of the narrowV orifices of preventingback-flashing .95

when the mixture is flowing with a velocity less than the rate ofpropagation of inflammation will be maintained.

This burner provided with velocity reducing means suchias that shown inFig. 4 need 100 not have its discharge orifices of such small width asto' act as flame-interrupting orifices provided it is to be operatedonly with the mixture maintained under such pressure ink the supplychamber that Ibackflashing will be prevented by reason of the fact thatthe mixture flows through the discharge orifices with a velocity greaterthan the rate .o-f

. propagation of inflammation of the mixture.

charge passage of decreasing cross-area terminating in a dischargeor1fice. The mixture to be burned is supplied to thelchamber through aninlet 16a, and the chamber may be formed with such an inlet opening ateach end either one to be Aused and the other to be pluggedfas shown,this both for convenience in manufacture and to enable the supplyconnection to be made to either end of the burner.

The upper portion of the body is made -sufiiciently thick so thatl theportions adjalmixture chamber gives an extended heat dissipating surfaceandsuch surface is desirably extended by providing fins or ribs 14a asshown; The lower portions of the body to which only a part of the heatreceived by the body is conducted, may be, and for lightness desirablyare, of less thickness than the portions nearer the discharge orifice.The burner is provided with a hearth layer 2O formed with a fia-ringopening registering with the discharge orifice, the hearth face of thebody being shown as extended to provide a sufficient support for suchhearth layer. The hearth 20 performs the same functions in this burneras in the burner previously described. As in the case of the burner ofFigs. 1 to 4, also, the discharge orifice may be of such small width asto serve as a flame-interrupting orifice, in

which case means for reducing the velocity of gas escaping from theorifice may or may not be provided as desired, or the orifice may be ofgreater width so that backflashing will be prevented only by causing themixture to fiow through the orifice with a velocity greater than therate of propagation of infiammation of the mixture, in which case.

a bed of pieces of refractory material or other'suitable velocityreducing means must be provided for causing the velocity of the escapinmixture to be reduced and combustion to localized. Such a bed of-broken'refractory material is shown in Fig. 5.v

, Figs. 8 and 9 illustrate a form of burner ,having a comparativelylarge number of small round discharge orifices opening through thehearth face of the burner body. The body is yformed -to provide amixture chamber 12b from which a plurality of discharge passages 13bextend through the body, said passages being constricted at their outerends to form the discharge orifices of the desired size. The passagesmay thus be considered as passages of decreasing cross area terminatingin a discharge orifice. The passages are shown as decreasing sharply orsuddenly in cross area, but the decrease might obviously be more orlessgradual as' inthe case of forms of apparatus illustrated by otherfigures of the drawings. The portions of the metal adjacent each orificewill be of increasing cross-section in the direction of the flow of heatfrom the walls of the orifice, and, as in the case of the burners beforedescribed, the `body is made of such cross-section or mass at any partthat such part shall have the required heat conducting capacity toconduct away all heat reaching such part from the walls of any of thedis-- charge orifices. For this purpose the upper part of the bodyorpart adjacent the hearth face thereof must ybe made sufficientlymassive and the discharge orifices must lbe suitably spaced. The portionof the body lying between the mixture chamber and the hearth face of thebody must be of sufficient thickness or depth in the direction of thedis-' charge passages, dependent onpthe number and arrangement of thepassages, to have at all oints the're'quired heat conducting capacity.As the inner or central portions of this part of the body receive lessheat than the outer portions which have to conduct away not only theheat from their immediately adjacent discharge orifices but also heatreaching them from the inner orifices, it is not necessary that theinner or central portion of thisv part ofthe body be made so thick asthe outer portions, and in order to reduce the amount of metal in theburner, therefore, it is desirable to so shape the upper wall 4of themixture chamber with relation to the shape of the hearth face that theportion of the body between the mixture chamber and the hearth faceshall be of decreasing thickness toward the center of the burner. burneris formed with a flat hearth face as shown, the upper wall of thechamber will be of generally concave form. The body is When the shown asprovided with heat dissipating fins f or ribs 14, and the side walls ofthe body are shown as extended downward tofurther increase the capacityof the body of disposing of heat received from the walls ofthe dischargeorifices,4 such extended portions of the walls being desirably ofdecreasing thickness as shown since the required heat conductingcapacity of portions more remote from the vorifices is .less than thatof nearer portions because of the fact that only a part of the heatreaches such remote portions. The burner is provided with a hearth layer20 of refractory material of low heat conductivity formed with outwardlyflaring openings 21 registering with the discharge orifices, such layerbeing similar to and serving the s ame purpose as the hearth layer ofthe burners previously described.

Fig. 10 shows a form of burner similar to that of Figs. 8 and 9, exceptthat the metal body is further extended so as to secure the necessarydissipation of heat tothe su-rrounding atmosphere without its beingpro-y vided with heat dissipating fins or ribs, and that the dischargeorifices or constricted portions of the discharge passages are providedby driving plugs 30 formed with the small discharge orifices 11c intothe outer ends of the passages 13 extending through i body.

Figs. 11 and 12l illustrate a form of burner in which heat conductorspass from the hearth face or Side of the body through the mixturechamber to the opposite side of the body. In the particular constructionshown in these figures the burner body comprises a heavy casing 40providing the side walls and bottom wall, or wall opposite t-he hearthwall, of -the mixture chamber 12d, and a hearth wall formed by enlargedor head portions of a plurality of conducting members or rods 41 whichare driven into openings in the bottom wall of the casing 40, and whichmost desirably extend through and beyond the bottom wall of the casingas shown. The heads of these conducting members or rods 41 are formed soas to provide between adjacent heads discharge orifices of the ,desi-redAShape and capacity.

The heads maybe square as shown, and each formed with a recess in twoopposite sides so that when the heads are arranged as shown and lincontact with eachother they will form ,a'wall having short slot shapedorifices 11d through which mixture will be discharged from the mixturechamberlQfd. The heavy casing 40 and the conducting bodies or rods 41are `made of ametal of suitable high heat conductivity, as in the caseof the'bodies of the other burners illustrated. When the burner is inoperation heat will be conducted by the conducting members or rodsdirectly to the bottom Wall of the casing 40, some of the heat beingconducted through the bottom wall of the casingt0 be discharged lfromitsside walls which are provided with suitable dissipating iins or ribs14, or from which heat may be Withdrawn by other suitable means. Some ofthe heat will pass on through the extended end portions of theconducting members or rods 41 to be discharged therefrom. The p partsbeing suitably proportioned, heat will be conducted away from the heatreceiving portions of the body and disposed of at the required rate tomaintain the walls of the discharge orifices suiiiciently cool and t-oprevent any part in contact with the mixture before it reaches the'orifices from becoming heated to the ignition tem- |The conductingbodies or rods perature. will of course be made of suitable size to havethe required heat conducting capacity, and the casing 40,*and especiallythe bottom Wall `thereof through which the conductingvv rods pass, willbeof sufiicient mass to carry away allheat received byit from the rods.The required heat conducting capacity of the f outer portions of thisbottom wall will be greater thanthat of the inner portion thereof, andthe inner portion may therefore be made thinner than the outer portion,as

shown-in the drawing. It will be seen that by providing the rods withslightly enlarged j heads the desired discharge orifices or shortpassages are provided and a sufficiently large flow space is alsoprovided between the rods to avoid any appreciable resistance to flow ofthe mixture t0 the orifices. The mixtufre chamber may be considered asdivided by the rods into connecting flow passages or discharge passageswhich are constricted'at their discharge ends to form the dischargeorifices, or which are of decreasing cross area terminating in thedischarge orifices. It will also be lseen that the metal adjacent eachorifice increases in cross-section in the direction of How of heat'therethrough from .the walls of the orifice.

What is claimed is: 3 j

1. A burner for explosive gaseous mixtures, comprising a structureproviding a body of metal of high heat conductivity inclosing andforming a mixture supply cham;

thereof to which heat is conducted from- A.

parts adjacent to which combustion takes place that'such portions shallhave sufficient. heat conducting capacity to conduct the heat reachingthem to a point from. which heat is discharged with `sufficient rapidityto keep the temperature of the -walls of the discharge orificesufiiciently low to maintain the flame-interrupting property .of theorifice and to prevent the walls of the discharge passage and the supplychamber from becoming' heated .to the ignition teinperature..

2. A burner for explosive gaseous mixwhich heat is conducted from partsadjacent to which combustion takes place that such portions shall havesufiicient heat conducting capacity to conduct the heat reaching vthemto a point from which heat is discharged with suflicient rapidity'toprevent -the walls of they supply chamber from becoming heated to theignition temperature'.

3. A burner for explosive gaseous mixtures, comprising astructure-providing al body of metal of high heat conductivity inclosingand forming a comparatively large mixture flow space extending close tothe placewhere combustion occurs and a mixture discharge orifice forlthe discharge of fmixture from such flow space to the place wherecombustion occurs, said orifice havl therethrough, and said body beingso formed and of such mass in portions thereof to" which heat 1sconducted from parts adjacent to which-combustion takes place that suchportions shall have suficient heat conducting capaci-ty to conduct theheat reach.- ing them to a point from which heat is discharged withsufficient rapidity to' keep the temperature of the walls of thedischarge orifice suficiently low to maintain the flameinterruptingproperty of the orifice and to prevent the walls of the dischargepassage and the supp-ly chamber from becoming heated to the ignitiontemperature.

4. A burner for explosive gaseous mixtures, comprising a structureproviding a body of metal of high heat conductivity inclosing andforming a comparatively large 'mixture iowl space extending close to theplace where combustion occurs and a mixture discharge orifice for thedischarge pf mixture from such flow space to the place where combustionoccurs, said body being so formed and of such mass in portions thereofto which heat is conducted fromf parts adjacent to which combustiontakes place that such portions shall have sufficient heat conductingcapacity to conduct the heat reaching them to a point from which heat is1^ discharged with suflicient rapidity to prevent the walls of .thesupply chamber from becoming heated to the ignition temperature.

5. A burner for explosive gaseous inixtures, comprising a structureproviding a.

body of metal of high heat conductivity inclosing and forming a mixturesupply chamber and a p-lurality of mixturedischarge passages ofdecreasing cross area terminating in discharge orifices having a widthsufficiently small to prevent backward propagation vor inflammationtherethrough, said body being so formed and of such mass in portionsthereof to which heat is conducted from parts adjacent to whichcombustion takes place that such portions shall have sufficient heatciiducting capacity to conduct the heat reaching them to a point fromwhich heat is discharged Awith sufficient rapidity to keep thetemperature of the walls of the discharge orifices suiiiciently low tomaintain the flame-interrupting property of the orifices and to preventthe walls of the discharge passages and ofthe supply chamber frombecoming heated to the ignition temperature. y

6. .A burner for explosive gaseous mixtures, comprising a structureproviding a body of metal of high heat conductivity inclosing andform-ing a mixture supply chamber and a plurality of mixture dischargepassages of decreasing cross area terminat- Vformed and of such mass inportions thereof to which heat is conducted from parts adjacent to whichcombustion takes place that such portions shallhave suiiicient heatconducting capacity to conduct the heat reaching t em to a point fromwhich heat is discharged with suiicient rapidity to prevent the walls ofthe discharge passages and of the supply chamber from becoming heated totheignition temperature.

7. A burner for explosive gaseous mixtures, comprising a structureproviding a body of metal of high heat conductivity, a mixture supplychamber, and a discharge orifice opening through the body for thepassage of mixture from the supply chamber to the place where themixture burns, `the portions of the body adjacent the orifice being ofrapidly increasing cross-section in the directlon of the fiow of heatthrough the body from the walls of the orifice, and the body being ofsuch cross-section or mass at any part that such part shall have therequired heat conducting capacity to conduct `away heat reaching suchpart from-the portions adjacent the discharge orifice at a ratesuflicient to prevent the walls of the supply chamber frombecomingheated to the ignition temperature.

8. A burner for explosive gaseous mixtures, comprising a structureproviding a body of metal yof high heat conductivity, a mixture supplychamber, and a discharge orifice opening throughthe body for the passageof mixture from the supply chamber to "the place where the mixtureburns, said discharge orifice having a width sufficiently small toprevent backward propagation of inflammation therethrough, and theportions of the body adjacent the orifice being of rapidly increasingcross-section in the direction of the iiow'of heat through the body fromthe walls of the orifice, and the body being of such cross-section ormass at any part that such part shall have the required heat conductingcapacity to conduct away heat reaching such part from the portionsadjacent the discharge orifice at a rate suiiicient to keep thetemperature of the walls of the orice sufiiciently low to maintain theiameinterrupting property of the orifice and to prevent the walls of thesupply chamber from becoming heated to theignition temperature.

9. A burner Jfor explosive gaseous mixtures comprising a structureproviding a body of metal of high heat conductivity, a mixture supplychamber, and a discharge orice opening through the body for the passageof mixture from the supply chamber to the place where the mixture burns,the portions of the body adjacent the orifice bein of rapidly increasingcross-section in the irection of the iow of heat vthrough the body fromthe Walls of the orifice, and the body being of such cross-section ormass at any part that such par-t shall have the required heat conductingcapacity to conduct away heat reaching such part from the portionsladjacent the discharge orifice at a rate suilicient to prevent theWalls of the supply chamber from becoming heated to the ignitiontemperature, and means for causing unburned mixture escaping from thedischarge orifice With a velocity greater than the rate of propagationof infianxmation to spread out with rapid reduction of flow velocity.

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Y of the body adjacent the 10. A burner for explosive gaseous mixtures,comprising a structure providing a body of metal of high heatconductivity, a mixture supply chamber, and a discharge orifice openingthrough the body for the passage of mixture from the supply chamber tothe place Where the mixture burns, said discharge orifice having a Widthsnfiiciently small to prevent backward propagation of infiammationtherethrough, and the portions orifice being of rapidly increasingcross-section in the direction of the flow of heat through the body fromthe Walls of the orifice, and the body being of such cross-section ofmass at'any part that such part shall have the required heat conductingcapacity to conduct away heat reaching such part from the portionsadjacent the discharge orifice at a ratevsufiicient to keep thetemperature of the walls of the orifice sufiiciently lovv to maintainthe fiame interrupting property of the orifice and to prevent the Wallsof the supply chamber from becoming heated tothe ignition temperature,and means for causing unburned mixture escaping from the dischargeorifice With a velocity greater than the rate of propagation ofinflammation to spread out with rapid reduction of fioW velocity.

11. A burner for explosive gaseous mixtures, comprising a structureproviding a body of metal of high heat conductivity, a mixture supplychamber, and a discharge orlfice opening through the body for thepassage of mixture from the supply chamber to the place Where themixture burns, the portions of the body adjacent the orifice being ofrapidly increasing cross-section in the direction of the fioW of Vheatthrough the body from the Walls ofthe orifice, and the body being ofsuch cross-section or mass at any part that such part shall have therequired heat conducting capacity to conduct away heat reachin such partfrom the portions adjacent the cdischarge orifice at a rate sufficientto prevent the walls of the supply chamber from becoming heated to theignition temperature, and means for Withdrawing heat from said body.

12. A burner vfor explosive gaseous mix- .tures, comprising. a structureproviding a body of metal of high heat conductivit a mixture supplychamber, and a discharge orifice opening through the body for thepassage of mixture from the supply chamber to the place Where themixture burns, the portionsI of the body adjacent the orifice being ofrapidly increasing cross-section in the direction of the fiovv of heatthrough the body from the Walls of the orifice, and the body being ofsuch cross-section or mass at any part that such part shall have therequired heat conducting capacity to conduct away heat reaching suchpart from the portions adjacent the discharge orifice at a ratesufficient to prevent the Walls of the supply chamber from becomingheated to the ignition temperature, and heat dissipating` fins forwithdrawing heat from the body and discharging it to the surroundingatmosphere.

13. A burner for explosive gaseous mixtures, comprising a structureproviding a' body of metal of high heat conductivity, a mixture supplychamber, and a discharge orifice opening through the body Jfor thepassage of mix-ture from the supply chamber portions of the bodyadjacent the orifice being of rapidly increasing cross-section in thedirection of the fiow of' heat through the body from the Walls, of theorifice, and the bodyv being of such cross-section or mass at any partthat such part shall have the re- I quired hea-t conducting capacity toprevent the Walls of the supply chamber from becoming heated to theignition temperature, 10o and a hearth formed by a layer of refractorymaterial of low heat conductivity having a flaring openingregistering'with the discharge orifi 14. A 'burner for explosive gaseousmix- 105 tures, comprising a structure providing a' bodyjofmetal of highheat conductivity, a mixture supply chamber, and a discharge orificeopening -through the body .for the susv passage of mixture from thesupply chambody from the Walls of the orifice, and the 115 body being ofsuch cross-section or mass at any part that such part shall have therequired heat conducting capacity to prevent the Walls of the sulpplychamber from becoming heated to Ithe ignition temperature, a hearthformed by a layer of refractory 'material of low heat conductivityhaving a flaring opening registering with the dis- 77charge orifice,anda combustion localizin bed formed by ypieces of refractory materiaplaced Within the flaring opening of the hearth.

15. A burner for explosive gaseous mixtures, comprising a structureproviding a body 0f man of high heat conductivity, s me di. mi

. mixture supply chamber, and a plurality of heatthrough the body fromthe walls of thei orifice, an'd the body being of such cross-y sectionor mass at any part that such partshall have the required heartconducting capacity to conduct away heat reaching such I part vfrom theportions adjacent the discharge orifices at a rate sufficient to pre-Avent the walls of the supply chamber Jfrom becoming heated to theignition temperature.

16. A burner for explosive gaseous. mixtures, comprising a structureproviding a body of metal ohigh heat conductivity, a

mixture-supply chamber, and a discharge passage leading from 'the supplychamber through the bodv, said passage being constricted at itsdischarge end to form a discharge orice, the portions of. the bodyadjacent the discharge orifice 'being of rapidly increasingcross-section in the direction of fiow of heat through the body from thewalls of .the orifice, andsaid body being of such cross-section or massat any part that such part shall have the required heat conductingcapacity to conduct away heat reaching such part from the portionsadjacent the discharge orifice at a rate sufiicient to prevent the wallsof rthe passage and of the supply chamber from becoming heated to theignition temperature.

17. A burner for explosive gaseous mixtures, ,comprising'a structureproviding a body of metal of high heat conductivity, a mixture supplychamber, and a plurality of discharge passages leading from the supplychamber through the lbody to the place where the mixture burns., saidpassages being 'constricted aft their discharge ends to form dischargeorifices, the portions of thel body adjacent each orifice being 'of-rapidly increasing cross-section in the direction of f iow of heatthrough the body from the walls of the orifice, and said body being ofsuch cross-section or mass at'any part that such part shall have therequired heat conducting capacity I to conduct away heat reachin suchpant from the portions adjacent the discharge orifices at a raiesufficient to preventv the .walls of the Ipassages and of thesupplyjchamber from becoming heated to the ignition temperature. Y

18. A burner for explosive gaseous mixtures, comprising a structureproviding a body of metal of high heat conductivity, a mixturev supplychamber, an'd a yplurality of' discharge passages leading from the'supply chamber through the body, said passages being constricted attheir discharge ends to form dischar e orifices havin a widthsufficiently smal toprevent bac {Ward propagartiony of inflammationtherethrough, theportions 'of the body adjacent each orice being ofrapidly increasingjcross-section in the direction of flow of yheatthrough the body from the walls of the orifice, and said body being ofsuch cross-section or mass at any part that such` pant shall;l have therequired. heat conducting capacity to conduct away heat reaching suchpart from the portions adjacentthe discharge orifices at a ratesufficient to keep the temperature of the walls of the dischargeorifices sufiiciently low to maintain the dame-interrupting property ofthe orifices and to prevent the Walls of the discharge passages and ofthe supply chamber from becoming hearted tov the ignition temperature.

19. burner for explosive gaseous mix- 85 tures, comprising a structureproviding a body of metal yof high heateconductivity, a mixture supplychamber, fand a plurality of discharge passages leading from the supplychamber. through the body, said passages being constricted at theirdischarge ends to Jform discharge orifices having a width sufficientlysmall to prevent backward propagation of' inflammation therethrough, andsaid body being of such cross-section or 95 mass at any part that suchpant shall have 'the required heat conducting capacity to tures,comprising a structure providing a body of metal of high heatconductivity, a mixture supply chamber, and -a plurality of dischargepassages leading from the supply chamber through the body, said passagesbeing constricted at their discharge ends to form discharge-orifices,the portions of the bodyadjacent each orifice being of rapidlyincreasing cross-secti-on in the direction of How of heat through thebody from the walls of the orifice, and said body being of suchcross-sectionor mass at any part that such part shall have the requiredheat conducting capacity to conduct away heat reaching such part fromthe portions adjacent the discharge orifices at a rate sufficient to`'prevent the walls of the passages and of 125 the supply chamber frombecoming heated to the ignition tempera-ture, and means for causingunburned mixture 'escaping from the discharge orifices with a velocitygreater than the rate of propagation of inflammavtion to spread out withreduction of fiow velocity.

21. A burner for explosive gaseous mixtures, comprising a structureproviding a Ibody of metal of -high heat conductilvlty, a mixture supplychamber, and a discharge passage leading from the sulpply chamberthrough the body of decreasing cross area and terminating in anelongated or slot shaped discharge ori-fice, the portions of the bodyadjacent the orifice being of rapidly increasing cross-section in thedirection of flow of heat through the |body from the walls of theorifice, said body being of such cross-section or mass at any part thatsuch part shall have the required heat conducting capacity to conductaway heat reaching such part from the portions -adjacent thedischarge'orifice at a rate sufficient to prevent the walls of thepassage and of the supply chamber from becoming heated to the ignitiontemperature.

2:2. A burner for producing iby the combustion of an explosive gaseousmixture a substantially continuous incandescent su-rface of considerableextent, comprising a structure providing a mixture supply chamber havinga wall formed-by a lbody of metal of high heat conductivity, a pluralityof discharge passages extending from the sup ply ch'amber through said|body, said p-assages Ibeing constricted =at their discharge ends toform discharge orifices which are close together and at which themixture burns, and a hearth for-ined by a layer of solid refractorymaterial on the outer face of said body having openings registering withthe discharge orifices, said body being of such cross-section or mass atany part that such [part shall have the required heat conductingcapacity to conduct aWav heat reaching such part from the walls of thedischarge orifices at a rate sufficient to prevent the walls of thepassages from becoming heated to the ignition temperature.

23. A burner for producing by the combustion of an explosive gaseousmixture asubstantially continuous incandescent surface of considerableextent, comprising a structure providing a mixture supply chanr berhaving a wall formed by a body of metal of high Iheat conductivity, aplurality of' discharge passages extending from the sulpply chamberthrough said body, said passages 'being constricted at their dischargeends to form Idischarge orifices having a width sufficiently small toprevent backward propagation of inflammation therethrough and which areclose together and a-t which the mixture burns, and a. hearth formed bya layer of Solid refractory material on the olhter face of said bodyhaving openings registering with the discharge orifices, said body beingof such cross-section or mass at any par-t that such part shall have therequired heat conducting capacity to conduct away heat reaching suchpart from. the Walls of the discharge orifices at a rate sufiicient tokeep the temperature of the walls Y of the discharge orificessufficiently low to maintain the fiamme-interrupting property of theorifices and to prevent the walls of the passages from becoming heatedto the ignition temperature. p l

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

CHARLES E. LUCKE.

Witnesses:

DAVID C. LEWIS, A. L. KEN1'.

